Generally, purity is very important for chemicals used in a semiconductor manufacturing process, and, thus, the chemicals need to maintain high purity. Therefore, glass bottles recognized as being safest to maintain high purity have been mostly used.
The problem here is that a toxic chemical accommodated in the glass bottle may leak to the outside due to breakage of the glass bottle and then directly or indirectly cause contamination of humans, systems, facilities, and semiconductor products, and the glass bottle is highly likely to directly harm and hurt human skin or the like by its nature.
Actually, such glass bottles are very frequently moved to be coupled or removed in semiconductor manufacturing plants, and in such a case, many accidents of breakage of glass bottles have occurred and have been greatly reported in the media.
As described above, due to a greater concern over environment and safety in recent years, in case of leakage of a toxic material caused by breakage of a glass bottle accommodating a chemical, the workers may be physically damaged first and the semiconductor manufacturer's public image may also be damaged. Therefore, it is actually necessary to actively prepare for it.
Meanwhile, in recent years, the glass bottles have been substituted by plastic ones to solve the conventional problems of the glass bottles. However, containers made of plastic cannot completely maintain purity of a chemical solution due to elution. Therefore, the use of glass bottles is expected to last for a long time.
As a prior art document relating to suppression of leakage of a chemical solution which may occur when a glass container accommodating a chemical solution is damaged on move, U.S. Pat. No. 6,817,485 (Nov. 16, 2004) discloses methods for discharging high-purity chemicals from an inner container in a protective pressure container.
The above-described document provides a dual structure including a separate protective pressure container encompassing an inner container accommodating a chemical and discloses a method of stably discharging the high-purity chemical through a liquid discharge pipe placed inside the inner container, but does not disclose any structure relating to a method of separating the protective pressure container to expose the inner container accommodated in the protective pressure container and any method of suppressing leakage of the chemical by the protective pressure container in case of damage to the inner container.